A gas turbine engine generally includes a compressor section, a combustion section, a turbine section, and an exhaust section. The compressor section progressively increases the pressure of air entering the gas turbine engine and supplies this compressed air to the combustion section. The compressed air and a fuel (e.g., natural gas) mix within the combustion section and burn in a combustion chamber to generate high pressure and high temperature combustion gases. The combustion gases flow from the combustion section into the turbine section where they expand to produce work. For example, expansion of the combustion gases in the turbine section may rotate a rotor shaft connected to a generator to produce electricity. The combustion gases then exit the gas turbine engine through the exhaust section.
The turbine section generally includes a plurality of blades coupled to a rotor. Each blade includes an airfoil positioned within the flow of the combustion gases. In this respect, the blades extract kinetic energy and/or thermal energy from the combustion gases flowing through the turbine section. Certain blades may include a tip shroud coupled to the radially outer end of the airfoil. The tip shroud reduces the amount of combustion gases leaking past the blade.
The blades generally operate in extremely high temperature environments. As such, the rotor blades may define various passages, cavities, and apertures through which cooling air may flow. In particular, the tip shrouds may define various cavities therein through which the cooling air flows. The cooling air then exits the blade through various ejection slots, including ejection slots in the tip shroud. Some of the ejection slots may enable the cooling air exiting the blade to mix with the high temperature combustions gases. Such mixing may negatively impact the efficiency of the turbomachine.